Untoward effects of rapid-acting antihypertensive agents

Potentially increasing rates of hypertension in women of childbearing age and during pregnancy--be prepared!

Abstract

The incidence of hypertension in young women is likely to increase in the near future because of the rising rates of the metabolic syndrome, obesity and dyslipidaemia worldwide. Consequently, more women will be on antihypertensive agents, which have the potential for teratogenecity. It is also likely that the increasing number of young women with essential hypertension who become pregnant will develop pregnancy-specific disorders such as pre-eclampsia. Health professionals should be aware of the effects of hypertension in women during the childbearing years, as well as the impact of pre-eclampsia on cardiovascular disease in later life. Pre-conception counselling skills, and knowledge on the use of antihypertensives and the changes that occur during pregnancy should be added to the clinical armamentarium of all health professionals.

Oral nifedipine versus intravenous labetalol in hypertensive urgencies and emergencies of pregnancy: a randomized clinical trial

BACKGROUND

Hypertensive crisis is an important cause of maternal and perinatal morbidity and mortality.

AIM

To compare the efficacy of oral nifedipine and intravenous labetalol.

MATERIALS AND METHODS

One hundred women with hypertensive crisis were randomized to receive either oral nifedipine 10 mg or intravenous labetalol 20 mg. Oral nifedipine was given 10 mg stat followed by 10 mg every 30 minutes up to a maximum of 50 mg. Intravenous labetalol was given 20 mg stat followed by 40 mg 30 minutes later then two more doses of 80 mg every 30 minutes up to a maximum of 220 mg. The primary outcome was the number of doses required to achieve target blood pressure (BP) and time required to reduce the mean arterial pressure by 25%. Secondary outcomes analysed included additional drugs required, resurgence of hypertensive crisis. Data were analysed using repeated measures analysis of variance (ANOVA), mixed ANOVA, unpaired t-test and chi square test and P value ≤0.05 was considered significant.

RESULTS

Systolic (SBP), diastolic (DBP) and mean arterial blood pressure (MAP) were lower than baseline at all time points of follow-up in both nifedipine and labetalol groups (P < 0.01). P < 0.05 by repeated measures ANOVA for overall trend of changes in SBP, DBP and MAP for within-group effects in both nifedipine and labetalol groups and P < 0.05 by mixed ANOVA for between-group effects during entire observation period. The magnitude of fall in SBP, DBP and MAP was greater in the labetalol group compared with the nifedipine group (P < 0.05). Target BP was achieved in 90% in the nifedipine group and 92% in the labetalol group. Maternal and fetal adverse effects were infrequent.

CONCLUSION

Both oral nifedipine and intravenous labetalol are effective in the treatment of hypertensive crisis. Intravenous labetalol may have benefits because it is more effective in reducing the SBP, DBP and MAP to target levels with a lower number of doses.

Maternal deaths associated with hypertension in South Africa: lessons to learn from the Saving Mothers report, 2005-2007

From 2005-2007, there were 622 deaths associated with hypertensive disorders of pregnancy. Eclampsia was the major cause of death (n = 344; 55.3%). There were 173 (28.3%) deaths due to pre-eclampsia, and 38 (6.1%) associated with chronic hypertension. Cerebral complications were the final cause of death in 283 (45.5%), while cardiac failure and respiratory failure were the final causes in 142 (22.8%) and 158 (25.4%), respectively. Major problems were identified in all areas of assessment. Non-attendance for antenatal care (n = 106; 19.4%) and delay in seeking help (n = 106; 19.4%) were major patient-related factors. Communication problems (n = 63; 10.8%) and lack of facilities (n = 50; 8.5%) were health administration issues. Health worker-avoidable factors included problem recognition, delay in referral and management at an inappropriate level of healthcare. Compared to the previous report of 2002-2004, there was a reduction in deaths due to hypertension.